Removable core breaker



REMOVABLECORE BREAKER v Q I v L. E. GARFIELD F iled June 19,1936

" IATTVORNEY" INVENTOR i r z m. u B

Dec. 15, 1936."

and u e. 15, 1936 y UNITED STATES PATENT-OFFICE"I Lewis E. Garfield, 3 m Tex" and! into Bullies Tool Company, Houston, Tex, corp H Application June 19, mes -m meats:

t i 7 Claims. 1(01. 25 m My invention relates to a device for use in breaking up cores which are formed bya; core drill in well drilling. It is adapted particularly for use in place of a retractible core barrel such as is now sometimes employed. {In well drilling where it is desirable to obtain samples of the formation at frequent intervals, a core drill is used. To avoid having to withdraw 'the drill stem to raise a sample of the formation to';the surface at each test, it is becoming common to drop a core barrel from the surface down into the drill andfwhen' 'a'sample hasentered the core barrel, togwithdraw the core barrelonly, leaving the drill stem and the-main drill in the hole. Some difllculty is experienced in thisprocedure in keeping the interior of the core drill free of material from the well bottom which tends to clog the passage for 'thebarrel." The central axial opening in. the drill may become so clogged and the core barrel seat so caked overwith mud, sand and detritus that the core barrel will not seat properly.

It is an object of my invention to provide a.

core breaker which can be dropped into fthe seat in the core bit andbe secured in place therein, to prevent the entrance of material and to break up and disintegrate this material sothat it may be washed away by the flushing fluid while the drillis in use and a core is not The invention includes the latchinsmechanism by means of which thepcore breaker is held in place while the drilling proceeds and it is an object to provide a. strong and eflicient latch which will automatically engage the. drill collar and hold the device in operating position.

It is also an obiectto provide an automatic latch which will be. capable of ready release .when a grappling device isemployed to .withdraw'the core breaker.

I desire to provide a. latch which will automatically be forced into, a rigid engagement with the drill and drill collar but which willrelease on an upward pullon the releasing mechanism. In the drawing herewith Fig. l is acentral longitudinal section through a core breaker shown in operative position in a core Fig. 2 is an enlarged section' -on theplane 2-,! of Fig. 1. I v

Fig.- 3 is a section of the core breaker on the plane 3-3 01118. 1.

Fig. 4 is a vertical, broken section on the plane 4- of Fig. 1.

In Fig. 1 the invention is shown as employed.

a seat no: the core breaker 6.

in a common type of core bit such as is ordinarily employed in softor semi-hard formations. It includesa; drill having a head i with laterally and forwardly projecting blades 2. The head has an axial opening therethrough, the upper end. of which has a threaded socket .3 for engage-' ment with the tubular drill collar. 4. The opening through the head diminishes in diameter downwardly and has a lower shoulder 5 to form There is a plurality of discharge nozzles'l for the flushing fluid on the forward sides ofthe cutting blades of the drill. These nozzles are preferably-formed with an interior lining of hard, wear resisting metal, as shown. Y Y

At theupperendof the drill collar is a shm't sub 8'for connection with the drill 'stem.. I

sub has a lower cylindrical passage 9101? an I interior diameter sufllciently restricted to-fit closely about the corebreaker when it is inserted into position. r .1 The core breaker Sis shaped to fit within the lower end of thedrill head andto engageclosely withthe shoulder i. It'has a forwardly extend-- ing' blade ill to engage the formation and cut the center of the hole. "The core breaker has a a reducedakial'opening to allow the stem l6 f of thelatching mechanism to move longitudinally therein. 1 I

- The latching dogs I! are formed on arms-l1 I the lower ends of which are pivotally supportedi- 3 upon a pin ll mounted transversely of a slotted 0' plug ll secured within the-lower end of the housing ll; Each arm is formedwith a'slot 20 neck ll extending upwardly andits'upper end therein which inclines outwardly and upwardly.

The outer side'ofeach dog at the upper end is formed with it toothed i'aw- 2|, the teethbeing cut, transversely and spirally to engage" screw threads within an outer bushing 22. Said threads are left hand "threads so that relative rotation of the bushing over the dogs move said dogs I a The bushing 22 is, as seen in Fig. 2, scoured to the inner wall of the drill collar by anchor downwardly.

pins 23 which extend through said wall and en- 1 gage within openings within ridges 24 formed radially upon the bushing. Betweensaid bushis t 40 H the stem downwardly to the position shown in ing and the drill collar, between said ridges 24, are fluid passages 25.

Working in the slqts 20 of the dogs is across pin 26. This pin, as seen in Fig. 4, is secured upon a head 21 at the lower end of the stem i6. Said head is slotted diametrically to receive the two latching dogs between the said walls of the slot shown at 23. It will be seen that the movement of the pin 25 upwardly in said slot will move said dogs inwardly out :of engagement with said bushing.

The stem I6 is formed witha circumferential groove 29 which, when said stem is moved upwardly into the passage through thehousing will receive therein latching balls 30 which tend to hold the stem elevated to maintain the dogs IS in retracted position.

- 'Ihe latching balls 30 are shown best in Fig. 3. They are mounted in radial openings in the housing and are held resiliently inward by leaf springs 3| which are secured, at a point spaced from the balls, to the outer surface of, the housing by set screws 32.

.At the upper end of the stem 16 is a'spear head 33 of ordinary form to be engaged by a grapple or overshot. Below this head the stem is threaded at 34 to receive a disc'35 and lock nut 39. The disc is of a suitable exterior diameter to fit slidably within the cylinder formed by'the the core barrel has been run to obtain a sample,

the core breaker is dropped intoposition. When dropped, the latching stem is drawnupwardly into position with the: balls 30 engaging in groove 29 of the stem, and thus holding the.

dogs retracted. When the core breaker engages the seat 5, the disc 35 will be in the cylindrical passage 9 and fluid pressure thereon will move 'Fig. 1. This downward movement will throw the dogs outwardly to engage the threads on the bushing 22 and will lock the corev breaker against upward movement. I.t-- the core breaker is not tightly locked, it will tend to resist rotation and the drill collar-bushing will screw it" downwardly to rigid engagement with the core breaker rotating with the drill.

When it is desired to remove the core breaker so that the core barrel may berun an dvershot of ordinary construction may. be'lowered and engaged about the spear head 33..An upward jerk on the stem will move the pin upwardly and withdraw the latching dogs and release the device so that it may be pulled upwardlyirom the drill and drill stem. When the latching dogs are in latching position as shownin Fig.1 thehead 21 on the stem will flt between the upper ends'ot the dogs It as shown and thus tend to hold said dogsin latched position. 7

It will be noted that the construction here shown is simple andstrong and has no parts liable to get out of order. The core'breaker is "moved into close engagement with its seat by the-positive screwing engagement of the latchinner seat, a core breaker shaped to flt said seat, a bushing in said drill collar spaced above said seat, said bushing being internally threaded, a barrel on said core breaker, latching dogs supported at the upper end of said barrel, teeth on said dogs formed to engage within said threaded bushing and means to force said dogs into position engaging said bushing, said dogs being then adapted to be screwed downward by said bushing.

2. A drill collar; a core ,drill thereon having an inner seat, a core breaker shaped to fit said seat, a bushing in said drill collar spaced above said seat, said bushing being internally threaded, a barrel on said core breaker, latching dogs supported at the upperend of said barrel, teeth on said dogs formed to engage within said threaded bushing and means actuated by pressure of fluid pumped down from above to force said dogs intoposition engaging said bushing, said dogs beingthen adapted to be screwed downward by said bushing. I

-3. A drill collar, a core drill thereon having aninternal seat, a core breaker formed 'to fit said seat and engage the well bottom, a, bushing in said drill collar jspaced above said seat and formed with an interior left hand thread; a'barrel upon said core breaker, a pair of dogs pivoted at the upper end of said barreL'means to hold said dogs normallyv inwardly, but releasable by liquid pressure;to, move said dogs outwardly 'into threaded engagement with said bushing.

4. A drill-collar, acor'e drill thereon having an internal seat, a core breaker formed to fit said seat and engage the well bottom, a bushing in said drill collar spaced above said seatjand formed with aninterior left hand thread, a barrel upon said corebre'aker, a pair of dogs pivoted at the upper end of said barrel, meansto hold said dogs normally. inwardly, butreleasable to move said dogs outwardly into threaded engagement with said bushing.

5. A drill collar, 9. core .drill thereon having an internal seat, a core breaker formed to fit said seat-and engage the well bottom, a bushing in said drill collar, spaced above said I seat and formed with an interior left handthread, a barrel upon said core breaker, a pairgof dogs pivoted 4 at the upper end of said barrel, means to hold said dogsnormally inwardly, but releasable by liquid pressure to move said dogs outwardly intov threaded engagement with said bushing and means'to lock said dogs in engagement with said 6. A drillicollar, a core drill thereon having an inner seat, acorebreaker shaped to fit said seat, a bushing in said 'collar above said seat,

means associated with said core breaker to engage said bushing and latch said core breaker ,on said seat, said latching means acting in -re-- sponse'torotationoi said collar relative to said core breaker. to force said core breaker tightly into said seat.

7. A drill collar, a core drill thereon having an inner se'at,a core breaker shaped to fit said seat,

latchingdogs' mounted .at the upperend'of saidcore breaker to engage said bushing with a left hand threaded connection, means to hold .said

dogs normallyretracted, and meansactuated by fluid pressureto move said dogs intolatching engagement with said bushing.

LEWIS 7E. 

